PLANETARY
SOCIETY INDIA
PRESS
MEET
FREQUENTLY
ASKED QUESTIONS AND ANSWERS
What
will happen on the night of 15/16 Feb Night ? At 12.55 a.m. a space rock called
“Asteroid 2012 DA14” will have closest approach to earth. It will flyby earth at distance of 27,700 km (above the surface of Earth) on 16th February at 12:10 a.m. IST. Size of this asteroid is estimated to be 45 meters (147 Feet). And it’s moving at
speed of 7.8 km/sec. This asteroid
was discovered on February 23, 2012 in
Spain. However there is no chance of this space rock hitting Earth or Moon now
or in near future.
Where
is this asteroid located and what does it do. When again it will have closest
approach to earth. When was the last time it came close to earth in the past ? Presently it orbits Sun once in 368 Days due
to present encounter it will reduce to 317
days.
The next time it will have closest
approach is in 15th February
2019 and would be at 6,91,64,078 km
i.e. around 7 Crore Km. Whereas it will be this close to earth in year 2046 on 16 February at distance of 66,608km. The last time it came close was on 16th February 2012 and was
at 26,06,840 km i.e. 26 Lakh Km. Presently
this is an object for fear mongering by some doomsayers on the web.
BACKGROUND/HISTORY
What
is an asteroid? Where are there found ? What is there origin?
Astronomically speaking Asteroids are a
class of small Solar System bodies in orbit around the Sun. The term
"asteroid" is ill-defined. It never had a formal definition, with the
broader term minor planet being preferred by the International Astronomical Union
from 1853. In 2006, the term
"small Solar System body" was introduced to cover both most minor
planets and comets.
In simple words asteroids are many of
rocky small bodies that orbit the Sun mainly in a flat ring called the asteroid
belt between the orbits of Planet Mars and Jupiter. It is
believed Asteroids are leftovers (during the process) of planet formation in
our solar system.
In
the past was Earth hit by Asteroids/Comets ? Is there any impact crater in India?
Yes there are 183 confirmed Impact
Craters across the world . Yes in India we have Impact Crater which is located
in Maharastra and it known as Lonar Crater .
How
Dinosaur got extinct from Planet Earth? The bulk of the evidence now suggests
that a bolide 5 to 15 kilometers (3 to 9 mi) wide hit in the vicinity of the
Yucatán Peninsula (in southeastern Mexico), creating the approximately 180 km
(110 mi) Chicxulub Crater and triggering the mass extinction. The asteroid
collision theory, which was brought to wide attention in 1980 by Walter Alvarez
and colleagues which links the extinction event at the end of the Cretaceous
period to a bolide impact approximately 65 million years ago.
What
are potentially Hazardous Asteroids? Potentially
Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that
can come closer to Earth than 0.05 AU. Presently none of the known PHAs is on a
collision course with our planet, although astronomers are finding new ones all
the time.
ALL
ABOUT ASTEROID 2012 DA14:
What is the weight of this object ? Its estimated to be 1,90,000
metric tons in weight. And is valued at 200 Billion Dollars.
Why is it so important ? Both Meteor Crater in Arizona, USA and the
impact in Tunguska, Siberia on June 30, 1908 were caused by roughly 140-foot
asteroids. The blast wave from the explosion of Tunguska asteroid flattened
about 2000 square miles of forest.
How
frequently such asteroids come closer to earth. What are chances of hitting
earth? Once
in 40 years asteroids with size of 2012 DA14 come close to earth. Whereas as
far such asteroids hitting is concerned once in every 1200 year we can expect
the asteroid to hit earth.
Will
it hit Earth in the future?Not in the next few decades, but there are small
chances that it will hit after that including a 1 in 7.5 million chance of
hitting in 2110.
IF
it hit Earth in the future, how big would the impact be?The energy
equivalent would be about that of a 2 to 3 megaton nuclear weapon (nearly 200
times the energy release at Hiroshima).
It would be comparable to the Tunguska impact in 1908 that leveled 2000
square kilometers of forest in Siberia.
It could destroy a city if it happened to hit one.
Could the DA14 asteroid collide with a
GEO satellite and disrupt service Or International Space Station? It may
be noted that the asteroid not only passes much closer
to Earth than the Moon's orbit, but even closer than geosynchronous satellites
(e.g., satellite TV satellites).While the trajectory of DA14 brings it closer
to the Earth than the communications satellites which orbit at about 36,000 kms
from Earth. So there is no risk of collision or disruption in service.
International Space Stations operates at 440 km from
Earth. Whereas majority of satellites operate from Low Earth Orbit. So this
asteroid is not in path or be danger for satellites.
How long ago did we learn of DA14 and its impending
close flyby of Earth? Can we say we had sufficient time. If at all it was on
collision course ? And what is the best we could have done ? DA14 was discovered on February 13, 2012, just one year
in advance of its close flyby of Earth. Had it been on a collision course with
Earth on February 15, 2013, there would not have been enough time to prepare a
mission to deflect it. While we would have been able to accurately predict its
impact location on Earth, our only possible response would have been to
evacuate the area and hope for the best.
Are
Scientists sure 16 Feb 2013. Asteroid 2012 DA14 will not hit Earth. What about
Others? Yes
prominently space organizations like NASA are keeping a close eye on this
asteroid. Importantly since over a year this object is being studied by various
observatories across the world. If at all if there was a indication of danger
alternative steps would have been taken to prevent and protect earth.
Can
we spot this Asteroid 2012 DA14? How? And Healthy human eye can see upto max.
6 Magnitude objects in sky. Hence this asteroid is not visible to naked eye but
can be spotted with help of Astronomical Telescopes. The
best viewing location for the closest approach will be Indonesia. Eastern
Europe, Asia and Australia are also well situated to see the asteroid.
How
it will appear from Telescopes/Binoculars? It will appear like fastly
moving Dot of light moving across
various pattern of Stars from South to North Direction in sky.
How many asteroids similar to DA14 or larger could
threaten Earth? There are roughly
a million asteroids larger than DA-14 whose orbits cross Earth’s orbit.
We know this because we have only discovered about ten thousand of these
asteroids, and we know that current telescopes have only effectively surveyed
about one percent of the volume of space in which these asteroids orbit.
Therefore we have only discovered about one percent of these asteroids!
Even though the risk of collision from DA14 is
extremely low, is there anything that could raise or change the risk of impact
for future generations? DA14’s
encounter with the Earth is so close that the asteroid’s orbit will be
significantly changed—from an asteroid “year” of 366 days to only 317 days. The
path will also be changed substantially, but we can calculate what that change
will be. DA14 will pass at large distances from the Earth every six to seven
years, with the next close approach in February 2047.
Will we be able to study the DA14 asteroid as it passes
the Earth? What might we hope to learn about it? The passage of an asteroid at such a small distance
from the Earth gives astronomers an unusual opportunity to study it in detail.
DA14 will be quite bright, and while probably not visible to the unaided eye,
it will be easily detectable with binoculars. Telescopes will be able to
collect a lot of information on the size, shape, rotation and composition of
DA-14. Radar observations will give us very precise measurements of its orbital
track, which will improve our knowledge of its future movements.
OTHERS:
How
to Spot Planet Jupiter, Saturn & Venus in the Sky ? These days after
Sunset one can see Jupiter above head and as the night progress one can it
movement across the sky till 12.30 in the night. Whereas Saturn can be located
in East Direction from 1.00 a.m. onwards. Venus though difficult to spot can be
seen minutes before Sunrise in East.
Why is B612’s Sentinel Space Telescope so
important? Sentinel is designed
to find and track Near Earth Asteroids—over 90% of the ones larger than 400
feet in diameter—and at least 50% of those 200 feet in diameter. Sentinel
will track these asteroids and give us decades of advance warning if any of
them will collide with Earth. This is enough warning that we will be able
to deflect an impending impact using well developed concepts like kinetic
impactors and gravity tractors. Sentinel will enable us to protect the
Earth by preventing future asteroid impacts.
What are the
various strategies to Stop Collision a incoming object ? 1. Asteroid
Tractors 2. Nuclear Explosions 3. Multiple Explosions 4. Kinetic impactor 5.
Solar Sail 6. Mass driver 7. Lots of
Paint It is not a matter of whether
there will be a dangerous impact, it is a matter of when. We need to find,
track, and characterize these objects and develop the technical and political
capability to deflect an asteroid.
ASTEROID MINING
How will asteroid
mining benefit humanity? * Water
resources: enabling the large-scale exploration of the Solar System. * Metal resources: for use in the growing
Earth economy * Scientific knowledge:
via spacecraft that are dramatically more cost-effective than current systems.
* Environment: off-planet resources will contribute to sustainability. *
Economic growth: large-scale exploration of space will create new jobs and
businesses.
Isn’t asteroid
mining science fiction? Exploring for alternate resource deposits is not
science fiction. Harnessing valuable minerals from a practically infinite
source will provide stability on Earth. The location of this source is a new
concept for many.. Also, asteroids are not processed bodies like the Earth and
the Moon, so their mineral deposits are more uniform throughout.
Aren’t asteroids
too remote and difficult to access? Actually, some near-Earth objects are
the most accessible destinations in the Solar System. There are over 1,500
asteroids that are as easy to reach as the Moon. These “space rocks” contain a
range of minerals, from water to platinum. Asteroid mining will provide
sustainable resources on Earth and will afford the availability to maintain a
human presence in space. They have Earth-like orbits and they also have small
gravity fields. So, we can reach them with very little propulsion. Not only are
they easier to reach, but it is relatively easy to depart from them and come
back to Earth because of their very small gravity field and their orbits. There
are over 1,500 asteroids that are as easy to reach as the surface of the Moon.
These ‘space rocks’ contain a range of minerals from water to platinum.
Asteroid mining will provide sustainable resources on Earth and will afford the
availability to maintain a human presence in space.
What is asteroid
prospecting? Is it possible to mine a body with a small gravity field? It is the process
of assessing the material resources an asteroid contains. Using telescopic
remote sensing, we can measure and value an asteroid in space with more ease
and precision than an ore body below Earth’s surface.
Conventional
terrestrial mining techniques rely on the presence of gravity, developed
over hundreds of years of our evolving understanding of the way materials
behave. The microgravity environment presents unique challenges for materials
acquisition and processing that require a different way of thinking about the
problem. Problems associated material transport and handling must be solved
with a new set of tools.
If some asteroids
are so resource-rich, wouldn’t extracting billions of dollars of resources
devalue the market? The
global economy is truly enormous – global GDP is over US$70 trillion annually. Second,
in order for every person on Earth to reach the standard of living enjoyed by
Americans today, global GDP would more than quadruple, reaching nearly $330
trillion annually.
Third, history shows that an increase in
ease of access to resources often leads to an expansion, not a shrinkage, of
the associated industries, as well as the development of new technologies that
use that resource.
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